Incinerators

ABSTRACT

The invention comprises an incinerator for burning refuse including a refractory lined front combustion chamber closed at the front by a pair of doors located one above the other and a secondary chamber at its rear, a baffle wall between the two chambers, air ducts along the sides of the combustion chamber venting primary and secondary air through said lining, fan means for supplying said air, a flat hearth for the combustion chamber, and a smoke outlet flue preferably from the secondary chamber. The smoke can be baffled in the secondary chamber to provide a duct and debris settling region and there can be a burner for unburned gases.

0 United States Patent [151 3,645,217

Akroyd Feb. 29, 1972 [54] INCINERATORS 3,446,] 63 5/1969 Sharpe ..1 10/8 3,487,792 l/l970 Dixon et a1... ..l10/8 [72] Akmyd England 3,495,555 2/1970 Boyd et al ..110/8 [73] Assignee: P. R. Akmud Limited, Harrogate,

Yorkshire, England Primary ExaminerKenneth W. Sprague Filed: Feb. 1970 Att0rneyStevens, Davis, Miller& Mosher [21] Appl. No.: 13,655 ABSTRACT The invention comprises an incinerator for burning refuse in- 52 us. 01. ..1l0/8 A, 1 10/173 R cluding a efracmy lined fmm cmbustin chamber at [51] Int. Cl. ..F23g 5/00 the from by a pair of doors located one above the other and a 58 Field of Search ..110/7 8 s A 18 173 Secondary chamber at Year a baffle between chambers, air ducts along the sides of the combustion [56] References Cited chamber venting primary and secondary air through said lining, fan means for supplying said air, a flat hearth for the com- UNITED STATES PATENTS bustion chamber, and a smoke outlet flue preferably from the secondary chamber. The smoke can be baffled in the seconda- 288,761 11/1883 Beckwlth ..1l0/173 X ry chamber to provide a duct and debris Settling region and 2,515,869 7/1950 Gregg et "110/18 there can be a burner for unburned gases. 2,925,054 2/1960 Sherman..... ....l l0/8 2,929,342 3/1960 Young ..l10/8 10 Claims, 11 Drawing Figures PAIENTEBFEB 29 1912 SHEET u as 4 'FIVG. 11-- INCINERATORS This invention relates to incinerators for burning refuse.

There are different types of incinerators and this invention is particularly concerned with the type in which the floor of the furnace chamber forms the hearth on which refuse or other material is burned. Forced-draught means are generally provided and usually there is a door-closed opening in what may be termed the front wall to give access for material to be bumed and another door-closed opening in the bottom region for ash withdrawal purposes.

According to the present invention there is provided an incinerator including a refractory lined front combustion chamber with a flat hearth, a pair of doors at the front open access end of the chamber and located one immediately above the other to combine in closing the said open end of the chamber, at least one secondary chamber at the other (rear) end of the combustion chamber, with a baffle wall between the two chambers, said chambers-being both disposed in a casing, the secondary chamber being situated at the rear of the casing, and fan means with air ducts leading therefrom extending into the front combustion chamber along its walls for venting air under pressure into said front chamber.

The invention includes an incinerator wherein the air ducts are located horizontally along the side of the front chamber in the refractory wall lining which includes air vents. The arrangement may include air ducts and vents in at least two different planes on each side of the front chamber.

Moreover, the air ducts may be tubes arranged along the walls in the lower region of the chamber to supply primary air laterally into the fire bed and in the upper region to supply secondary air over the fire bed.

The invention will now be more particularly described with reference to the accompanying drawings, in which:

FIG. 1 is a front elevation of an incinerator according to the invention;

FIG. 2 is a side elevation of the incinerator;

FIG. 3 is a sectional detail of one of the air inlet pipes and ducts;

FIG. 4 is a front view of a refractory two-part block providing air inlet means;

FIG. 5 is a sectional view of said block;

FIG. 6 is a sectional side view of a modified rear chamber;

FIG. 7 is a sectional plan view of FIG. 6 on line XX;

FIG. 8 is a sectional side view of another form of incinerator;

FIG. 9 is a sectional elevation on line A-A of FIG. 8;

FIG. 10 is a sectional view of line BB of FIG. 8, and

FIG. 1 1 is a substantially diagrammatic cross sectional view of an incinerator with cylindrical chambers.

In a particular embodiment of this invention the incinerator includes a metal shell 1 divided into a front combustion chamber 2 and a secondary rear fan chamber 3. The front chamber is lined on its bottom 4 (which forms the fire bed hearth), sides 5, rear 6 and top 7 with refractory material which provides an arched roof for the chamber. The open front end of the chamber is closed by a pair of hinged doors 8, 9, located immediately one above the other. The two doors are hinged at 10 and 11 on the same side and are furnished with clamping or other securing means 12 and 13 on the opposite side. These doors can be filled with refractory material and the horizontal joint 14 between the two doors is inclined transversely downwardly and outwardly. There may be asbestos or other fire-resistant packing material carried by one of the doors for sealing this joint when the doors are closed. Instead of the inclined joint, the upper edge of the lower door and lower edge of the top door can be level at this joint. Also there can be a downward extension of the front plate of the upper door to overlap this joint. The lower door is for use in giving access for the withdrawal of ash from the hearth 4.

To supply air to the combustion chamber 2, two pairs of tubes 15, 16 are secured to the inner face of the metal shell of the incinerator and such tubes are arranged horizontally with one pair 15 in the lower region of the combustion chamber to supply primary air into the fire bed, and the other pair 16 are in an upper region for the supply of secondary air. Holes are formed along the length of the tubes and these holes register with ports 17 in the refractory material to vent air into the chamber. These ports may be holes or slots or a long gap in the refractory material for each tube. Air is supplied to each tube from a connection box 18 in the rear chamber 3 to which an electrically driven fan unit 19 is connected. Flexible or other tubes 20 run from the connection box 18 to the air supply tubes 15, 16 and if so desired air controller damper or other means may be furnished for controlling the airflow to individual tubes.

A flue 21 leads out of the combustion chamber 2 through the top of the incinerator and means may be furnished for burning waste gases. Moreover, the aforesaid metal shell may be furnished with an outer casing with lagging or other insulation material between the shell and casing. If desired there may be an airgap between the shell and easing. It will be understood the air supply tubes 15 and 16 may be provided on the outer face of the steel shell or air ducts furnished in the refractory material. FIGS. 4 and 5 show a two-part block 22 with a slot forming the duct 17 and a rear recess in each part forming a passageway 23 with the shell 1 to replace a tube 15 or 16. Slotted blocks in a row, it may include recessed but unslotted blocks, form a long passageway for air from the fan unit in the chamber 3.

The construction may be modified by arranging the flue 21 to pass out of a settling secondary chamber 24 which can be of full depth behind the combustion chamber 2, or part depth, say the divided-off upper region of the fan secondary chamber 3. The outflow of smoke and gases from the combustion chamber can be round a central baffle wall 25 (FIGS. 6 and 7)" through openings 26 into the settling chamber, and under pendant bafile walls 27 to the flue 21. Alternatively, the smoke and gases may pass through an upper opening over the wall 25' into said chamber and against a pendant baffle wall to pass under it to the flue.

The means for burning waste gases or smoke in the flue 21 may be a gas ring with jets at an angle upwardly and also from a radial line to create a swirling or turbulent action. This burner ring may be at the base of a refractory lined chamber in the flue.

In FIGS. 8 to 10 openings 28 are formed in the rear baffle wall 6 of the chamber 2 and open into the side regions 30 of the rear secondary chamber 3 which is divided by the walls 29. Smoke and gases pass down said regions and through the gap 30 up into the chamber 3 to enter the flue 21. Thus a settling chamber is formed on each side of the hollow structure 31 which includes a burner 32 provided with a top flame spreader 33. The burner fires unburned gases and facilitates the updraught to the flue. Air vents are also included in the walls 5 of: the chambers 3a and in this construction the fan unit mounted: outside the end wall of the incinerator. In some constructions it may be policy to include an air duct 34 in the floor 4 of the chamber 2 to supply bottom primary air.

Instead of two hinged doors 8 and 9, at least the upper door may be hung or otherwise mounted to be slidable horizontally or vertically. Here again the joint between the doors may have" an overlapping flange or lip. With large incinerators the front door closed opening may be substantially the full depth of the chamber 2 but only part of the width of the chamber to reduce" the width, and thus the weight of the doors. Alternatively, on

large incinerators two doors may be provided with a cross and the other for the right hand vents to allow for separate air:

control.

The incinerator (FIG. 1 1) has a pair of cylindrical chambers 2 and 3 in alignment in a cylindrical body 35 and divided by a:

baffle wall 6. The chambers have a refractory lining 36 enclosed in a metal outer shell 37 and asbestos or other thermalinsulating material 38 is interposed between said lining and the shell. Conveniently the incinerator can have this cylindrical body 35 extending between a rear metal plate 39, which may have an inner refractory lining, and a front metal plate 40, which carries the double doors 8, 9 which may be round or octagonal. An outer casing 41 then extends between the front and rear plates 39, 40 and thus the two chambers 2 and 3 lie within an airspace 42 formed between the outer casing 41 and the cylindrical body 35. With this arrangement the air ducts can be in the form of pipes 43 mounted externally on the shell 37 and connected to a fan unit 18 which in this instance is arranged below and to one side of the cylindrical body within the casing 41. There can be an access door in the latter to the fan unit and the casing can have louvres or other openings for air to enter the space 42 to be drawn into the fan unit. The incinerator is furnished with a flat hearth 4, although it need not be so, and openings 26 are formed in the baffle wall for the passage of smoke or gaseous products of combustion to pass down the chamber 3, under battle walls 27 and then centrally up to the flue 21. The latter may be at the top as shown, or project horizontally rearwardly, and a gas or oil burner 44 is mounted to project into the chamber 3 to fire unburned gases.

With this construction externally the incinerator can be rectangular in shape with no protrusions apart from the front double doors. Whilst the incinerator can be fixed in position it may be of portable construction.

Any of the incinerators may have the flue 21 located for the smoke or gaseous products of combustion to rise vertically or pass horizontally from the incinerator. Moreover, the fan unit supplying air to the ducts l5 and 16 or 23 may be positioned externally at the side or rear of rectangular shaped incinerators, and at the rear or underneath or the side of incinerators with a cylindrical body. Also, the smoke burner 35 may be mounted to fire into the chamber 3 from the rear or through a sidewall.

Any of the constructions shown in FIGS. 1 to may be furnished with a thermal insulation material or medium between the refractory lining 5, 7 and the metal outer shell 1.

What I claim is:

1. An incinerator for burning refuse, comprising a casing, combustion chamber disposed in said casing and having a flat hearth, a refractory lining for said chamber, one end of the chamber being open for access and normally closed by a pair of doors located one immediately above the other, a baffle wall at the rear end of the chamber, at least one secondary chamber disposed in said casing behind said baffle wall, an outlet for gaseous products of combustion which flow from the combustion chamber, air ducts along the sides of the combustion chamber with vents through its refractory lining in at least two different planes, and fan means connected to the ducts for supplying pressurized primary and secondary air through said vents to said combustion chamber.

2. An incinerator according to claim 1, wherein the air ducts are located horizontally along the sides of the combustion chamber in the refractory wall lining.

3. An incinerator according to claim 1, wherein the front combustion chamber communicates with the rear secondary chamber through at least one opening in said rear baffle wall, and further comprising baffle means in said rear secondary chamber to divert smoke and gases downwardly before rising to a flue, and at least one dust and debris settling chamber.

4. An incinerator according to claim 3, further comprising a flow path for combustion products which includes said combustion chamber, two side regions of the rear secondary chamber, said baffle means and a central region below a flue in said secondary chamber.

5. An incinerator according to claim 1, wherein the refractory lining is surrounded by a metal casing and thermal insulative material is interposed between the lining and easing.

6. An incinerator according to claim 1, including a burner for firing unbumed gases.

7. An incinerator according to claim 6, wherein the burner 

1. An incinerator for burning refUse, comprising a casing, combustion chamber disposed in said casing and having a flat hearth, a refractory lining for said chamber, one end of the chamber being open for access and normally closed by a pair of doors located one immediately above the other, a baffle wall at the rear end of the chamber, at least one secondary chamber disposed in said casing behind said baffle wall, an outlet for gaseous products of combustion which flow from the combustion chamber, air ducts along the sides of the combustion chamber with vents through its refractory lining in at least two different planes, and fan means connected to the ducts for supplying pressurized primary and secondary air through said vents to said combustion chamber.
 2. An incinerator according to claim 1, wherein the air ducts are located horizontally along the sides of the combustion chamber in the refractory wall lining.
 3. An incinerator according to claim 1, wherein the front combustion chamber communicates with the rear secondary chamber through at least one opening in said rear baffle wall, and further comprising baffle means in said rear secondary chamber to divert smoke and gases downwardly before rising to a flue, and at least one dust and debris settling chamber.
 4. An incinerator according to claim 3, further comprising a flow path for combustion products which includes said combustion chamber, two side regions of the rear secondary chamber, said baffle means and a central region below a flue in said secondary chamber.
 5. An incinerator according to claim 1, wherein the refractory lining is surrounded by a metal casing and thermal insulative material is interposed between the lining and casing.
 6. An incinerator according to claim 1, including a burner for firing unburned gases.
 7. An incinerator according to claim 6, wherein the burner is located in the rear secondary chamber beneath a region leading up to a flue.
 8. An incinerator according to claim 1, wherein the horizontal joint between the top and bottom doors is inclined transversely.
 9. An incinerator according to claim 1, wherein the horizontal joint between the top and bottom doors is stepped transversely to form an overlap.
 10. An incinerator according to claim 1, wherein at least one longitudinal air duct and vents are provided along the hearth of the combustion chamber. 